Fault under Japan nuclear plant 'may be active'

Nov 11, 2012 by Shingo Ito
Kansai Electric Power Co (KEPCO) engineers check readings at the company's Oi nuclear power plant in the town of Oi, Fukui prefecture in July 2012. Japan's only working nuclear power plant sits on what may be a seismic fault in the earth's crust, a geologist has warned, saying it is "very silly" to allow it to continue operating.

Japan's only working nuclear power plant sits on what may be a seismic fault in the earth's crust, a geologist has warned, saying it is "very silly" to allow it to continue operating.

Mitsuhisa Watanabe says the earth's plates could move under the Oi in western Japan, causing a catastrophe to rival last year's atomic disaster at —although some of his colleagues on a nuclear disagree.

"It is an active fault. The plates shifted some 120,000 to 130,000 years ago for sure," Watanabe, of Tokyo's Toyo University, told AFP.

"In research that I have conducted on active faults in Japan and overseas, structures built above them were all damaged" when they moved and caused an earthquake, he said.

Watanabe, a tectonic geomorphologist, is part of a five-member team tasked by the Nuclear Regulation Authority with looking into the tectonic situation underneath the plant, which houses the country's only working reactors.

Under government guidelines atomic installations cannot be sited on a fault—the meeting place of two or more of the plates that make up the earth's crust—if it is still classed as active, that is, one that is known to have moved within the last 130,000 years.

A positive finding would mean regulators must order the suspension of operations at the plant in Fukui prefecture.

But other scientists on the panel say it is too early to class it as an "active" fault that might pose a risk to the plant, calling for "a scientifically calm approach".

The team's head, Kunihiko Shimazaki, who is also a member of Japan's nuclear regulatory body, says the geological scarring they can see was probably caused by little more than a long-ago landslide.

Instead of the definitive green light that plant operator Kansai Electric Power (KEPCO) was hoping for, the committee last week said only that more work needs to be done.

"It's desirable for all members to reach a conclusion by consensus," Shimazaki said.

However Watanabe, asked if the government should allow KEPCO to continue running the plant at Oi, said: "It would be a very silly option."

"We would have learned nothing from Fukushima. I'm afraid we would see a repeat (of the disaster) one day."

He maintains that the plant could be vulnerable to a sizeable earthquake, which might "cause a very serious problem... similar to the Fukushima one".

But he stresses that the science thus far is simply not conclusive and argues work should halt out of an abundance of caution.

"We are not seeking to decommission the plant," Watanabe said. "We should first stop operation and then carry out underground investigation thoroughly before reaching a conclusion."

All Japan's nuclear reactors were shut down in the months after the disaster at Fukushima, when an earthquake-sparked tsunami knocked out cooling systems and caused meltdowns that scattered radiation over a large area.

Hundreds of thousands were made homeless and tracts of prime agricultural land were left unfarmable.

Despite widespread public fears over the safety of nuclear power, Prime Minister Yoshihiko Noda in June ordered the restarting of reactors at Oi amid fears of a summer power shortage.

That ended a brief nuclear-free period for a country that—until the Fukushima disaster—had relied on atomic power for around a third of its electricity needs.

The move was welcomed by the influential business lobby but was deeply unpopular with a vocal anti-nuclear movement. Regular anti-nuclear protests continue to be held in Tokyo.

On Sunday, the 20-month anniversary since the Fukushima disaster, several thousand anti-nuclear protesters rallied in Tokyo's government district.

"No need to wait for the panel's finding! We must stop the Oi plant now!" one shouted outside the parliament building.

With a possible eye on the general election expected over the coming months, the government announced in September it would work towards a policy of phasing out by 2040.

Critics rounded on the announcement as both populist and "incoherent" because it contained get-out clauses that would mean as-yet unfinished nuclear plants would still come online.

Watanabe said a heavy burden rests on those tasked with ensuring public safety, citing the jail sentences imposed on six seismologists in Italy after a court said their underestimation of the possible effects of an earthquake had contributed to the death toll in the central city of L'Aquila.

"We have to sound the alarm as soon as we find the possibility of active faults," he said. "The accident in Fukushima had really never been imagined. Scientists must learn from that."

Explore further: Pollution top concern for U.S. and Canadian citizens around Great Lakes

add to favorites email to friend print save as pdf

Related Stories

Japan reactor back to full power after shutdown

Jul 09, 2012

A nuclear reactor in western Japan began full operations on Monday, the first restart since the country shut down its atomic stations in the wake of last year's crisis at the Fukushima Daiichi plant.

Japan to go nuclear-free for first time since 1970

May 04, 2012

Japan is set to go without nuclear energy for the first time since 1970 from Saturday, when the last operating reactor shuts down for maintenance, heightening fears of a looming power crunch this summer.

Japan vows to continue nuclear plant exports

Aug 05, 2011

Japan said Friday it will continue exporting atomic power plants, despite uncertainty over its own use of them as it continues to grapple with a crisis at the tsunami-hit Fukushima nuclear plant.

80% in Japan 'support nuclear phase-out'

Mar 18, 2012

Eighty percent of Japanese want to phase out the country's reliance on nuclear power and eventually eliminate it, a poll said Sunday, a year after Japan was hit by a massive nuclear disaster.

Japan's Hamaoka atomic plant to build huge seawall

Jul 22, 2011

Chubu Electric said Friday it will build an 18-metre (60 foot) anti-tsunami seawall to protect its ageing Hamaoka nuclear plant located near a faultline in a region seen as vulnerable to earthquakes.

Recommended for you

Obama launches measures to support solar energy in US

Apr 17, 2014

The White House Thursday announced a series of measures aimed at increasing solar energy production in the United States, particularly by encouraging the installation of solar panels in public spaces.

Tailored approach key to cookstove uptake

Apr 17, 2014

Worldwide, programs aiming to give safe, efficient cooking stoves to people in developing countries haven't had complete success—and local research has looked into why.

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

antialias_physorg
not rated yet Nov 12, 2012
Under government guidelines atomic installations cannot be sited on a fault

Which is sort of hard because nuclear reactors need lots of water water. Water flows in rivers. Guess where many rivers flow in. Yep: Earthquake faults.
ValeriaT
not rated yet Nov 12, 2012
..The accident in Fukushima had really never been imagined. Scientists must learn from that..
Of course they imagined it, but the risk of tsunami was deeply understimated at Japan. In the same area the tsunami reached the height 24 m in 1933, the height 38 m in 1896. The Fukushima was destroyed with tsunami wave lower than 14 meters. It means, the Fukushima plant was not prepared even to cent-year's flood - is it really so unimaginable? These Japanese just saved their money during building of Fukushima nuclear plant above the acceptable level.

More news stories

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...